Boring-tool holder.



. ,PATENTED 001. 17, 1905. 0. G. OTEWALT.

1 m HA n wm TN m T RN 0L M UNITED STATES PATENT OFFICE.

ORRIS Gr. OTEWALT, OF SPRINGFIELD, OHIO, ASSIGN OR TO THE WESTERN MANUFACTURING COMPANY, OF SPRINGFIELD, OHIO, A CORPORATION OF OHIO.

BORING-TOOL HOLDER.

Specification of Letters Patent.

Patented Oct. 1 7, 1905.

Application filed April 18, 1904. Serial No. 203,582.

1'0 all whom it may concern.-

Be it known that I, ORRIs Gr. OTEwALT,a citizen of the United States, residing at Springfield, in the county of Clark and State of Ohio, have invented certain new and useful Improvements in Boring-Tool Holders, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to boring-tool holders, and has for its object to provide a toolholder adapted for use in connection with a lathe, said holder being adapted to be secured directly in the usual tool-post of the latheslide and being constructed and arranged to firmly support the boring-tool, permit its ready vertical adjustment, and assure an accurate horizontal position of the bar which carries the boring-tool proper, the structure as a whole being simple, compact, and inexpensive.

To these and other ends my invention consists in certain novel features which I will now proceed to describe and will then particularly point out in the claims.

In the accompanying drawings, Figure 1 is 'a perspective view of a structure embodying my invention in its preferred form. Fig. 2 is a central horizontal plan section thereof. Fig. 3 is a vertical sectional view taken on the line as m of Fig. 2 and looking in the direction of the arrows, and Fig. 4 is a detail perspective view of the seat-bar detached.

In Fig. 2 of the saiddrawingsI have shown my improved holder as mounted in the usual tool-post 1 of a lathe, the holder being provided with a shank or tailpiece 2, which adapts it to lit therein. This shank extends from the rear of a vertical head 3, which is provided near each end with a vertical slot 4. Through each slot 4 extends a bolt 5, in the form of an eyebolt, having a head 6 projecting beyond the outer face of the head 3 and having an elongated slotor opening? formed therethrough. This slot or opening is preferablyrounded at its outer end, as indicated at 8, to lit the boring-bar 9, the other end of the slot 7 being preferably flat, as indicated at 10. The bolts 5 extend beyond the rear face of the head 3, and on these projecting ends are mounted nuts 11, washers 12 being interposed between said nuts and the rear face of the head 3. The slots 4: are preferably of increasing width from front to'rear, so as to prevent the bolts from binding therein and permit the parts to adjust themselves during the clamping operation. The bolt-heads 6 are of less width than the slots 4 at their front ends, so as to permit said heads to engage said slots when the parts are in clamping position, and thus firmly hold the bolts against rotation.

. 13 indicates a seat-bar interposed between the boring-bar 9 and the front face of the head 3. Said seat-bar extends through the slots or openings 7 of the bolts 5 and is preferably notched or recessed upon its upper and lower edges and at the back, near each end thereof, as indicated at 14:, to engage with the adjacent portions of the bolt-heads 6 and prevent longitudinal motion of the seat-bar relatively to the bolts 5 and head 3. The body of the bar 13 is wider from top to bottom on that side of the recesses 14: nearest the center of the bar than the extreme length of the slots 7 in the bolt -heads 6, while those portions of the body of the bar 13 lying outward from said notches or recesses are of less width than the extreme length of the slots 7, so that the seat-bar can'only be engaged with and disengaged from the bolt-heads when the bolts are removed from the head 8, thereby preventing the seat-bar from slipping out of engagement with the bolts while the holder is assembled.

The front face of the head 3 is preferably provided with horizontal serrations or teeth 15 to engage with corresponding serrations or teeth 16 on the rear face of the seat-bar 13. I prefer to arrange these horizontal serrations in vertical series on each side of each slot 4 and on the corresponding'parts of the back of the seat-bar. The front face of the seat-bar is provided with V-shaped grooves 17 at each end to form a firm bearing for the boring-bar 9, the central portion of the face of said seatbar being recessed or more deeply grooved, as indicated at 18, to cause the boring-bar to be gripped more firmly near the ends of that portion thereof which lies within the holder, and thus give the boring-bar a firm support. Each groove 17 is preferablyinterrupted as to that portion thereof which lies within the corresponding bolt-head 6 by a recess or deeper groove 19, so that the boring-bar is gripped on one side of its longitudinal axis between the bearing-seats 17, which lie on opposite sides of the bolt-head 6, said bolt-head 6 gripping the boring-bar on the other side,

of its longitudinal axis alongaportion thereof lying between the seats 17, thus materially increasing the firmness of the grip by which the boring-bar is held.

It will be understood that the holder is adapted for use with any suitable boring-tool; but I have shown it in connection with a wellknown form of tool comprising a boring-bar 9,'circular in cross-section and carrying the boring-tool proper,20,at its forward end. The boring-bar is inserted in the slots 7 in the heads of the boit 5, whereupon a tightening up of the nuts 11 will-firmly clamp the boring-bar against the seat-bar andthe seat-bar against the front face of the head. The boringbar may be as readily released, so as to adjust it longitudinally-or rotatively, by slightly turning back the nuts 11, and this may be done without affecting the'vertical adjustment of the boring-bar or requiring its readjustment vertically when it is again clamped, since the slight loosening of the nuts referred to is not suificien't to permit the serrations on the head and seat-bar to become disengaged. The vertical height of said bar*may be readily adjusted by turningback said nuts sufiiciently to permit the serrations 15 and 16 to be disengaged, whereupon the bolts, seat-bar, and boring-bar may be vertically adjusted relatively to the head and quickly and firmly secured in their adjusted position. The horizontal serrations insure the horizontalposition of the boring-bar and also take the strain of maintaining it in that position from the nuts 11 to a great extent. Moreover, the construction is such that the'boring-tool proper may be held to its work by the grip of a single one of the two eyebolts, the seat-bar operating in connection with said eyebolt to hold the boring-bar rigidly in position, and this increases the range of work by permitting the boring-bar to be drawn out until its rear end, farthest from the boring-tool proper, is gripped only by'that one of the eyebo'lts nearest the work.

I do not wish to be understood as limiting myself strictly to the precise details of construction hereinbefore described, and shown in the accompanying drawings, as the same may obviously be modified without departing from the principle of my invention. For instance, while the interposition of the seat-bar between the head 3 and boring bar'possesses the advantages which I have hereinbefore pointed out my invention in its broadest form contemplates the omission of this seat-bar,'in which case the eyebo'lts will clamp the boring-bar directly against the vertical=face of the head 3.

The body of the holder, comprisingthe shank 2 and head 3, has a suitable bearing upon the top of the slide, being provided for that purpose with three bearing-surfaces 21 on its under side, two of them located at the ends of the head 3 and the third located at the end'of the shank 2, as shown in Fig. 1. This gives the attachment a firm bearing upon the In addition to this said body is provided at that end of the head nearest the work with a downwardly-extending lug or projection 22, which is adapted to bear against the edge of the slide, and thus resist the thrust which is transmitted from the work through the boring-bar to the holder. I have found in practice that, whereas it requires very great power applied to the clamping-screw of the tool-post tohold the attachment firmly in place, when the abutment-lug 22 is not employed a very light pressure upon said clamping-screwis all that is required for this purpose-where the abutment-lug 22 is employed to take up the back thrust of the work.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

l. A boring-tool holder comprising a head provided with avertical slot, a bolt vertically adjustable in said slot, the bolt-head projecting beyond the front face of the holder-head and being itself horizontally slotted longitudinally of the bolt, the threaded portion of said bolt'projecting beyond the rear face of the holder-head, and being provided with a clamping-nut to bear against said rear face, and a seat-bar extending through the slot in the bolthead and arranged to bear against the front face of the head when the parts are in clamping position, substantially as described.

2. A boring-tool holder comprising a head provided with a vertical slot, a bolt vertically "adjustable in said slot, the bolt-head projectingbeyond the-front face of the holder-head and being itself horizontally slotted longitudinally of the bolt, the threaded portion of said bolt projecting beyond the rear face of the holder-head, and being provided with a clam ping-nut'to'bear against said rear face, and a seat-bar extending through the slot in the bolt-head and arranged to bear against the front face of the head when the parts are in clamping'position, the abutting faces of the seat-bar and head having-engaging serrations or teeth, substantially as described.

3. A boring-tool holder comprising ahead 'provided with parallel vertical slots, and bolts vertically adjustable in said slots, each bolt having its head projecting beyond the front face of the holder head and horizontally slotted longitudinally of the bolt, the threaded portion of each bolt projecting beyond the rear face of the holder-head and being provided with a clamping-nut to bear against said rear face, and a bearing-plate extending through the bolt-head slots and adapted to bear against the front face of the holder-head when the parts are in clamping position, the abutting faces of the seat-bar and holder-heads being provided with horizontal serrations or teeth, substantially as described.

4. In a boring-tool holder of the character described, the combination, with a head having vertical slots, and bolts vertically adjustable in said slots and having heads projecting beyond the front face of the holder-head and horizontally slotted longitudinally of the bolt, of a seat-bar extending through the slots of the bolt-heads and notched or recessed to engage and be held in position thereby, substantially as described.

5. In a boring-tool holder of the character -described, the combination, with a head having vertical slots, and bolts vertically adjustable in said slots and having heads projecting beyond the front face of the holderhead horizontally slotted longitudinally of the bolt, of a seat-bar extending through the slots of the bolt-heads and notched or recessed to engage and be held in position thereby, the body of said seat-bar between said bolt-heads being of a width greater than the bolt-head slots, and those portions of said bar lying outward beyond the bolt-heads being of less width than the length of said slots, substantially as de, scribed.

6. In a boring-tool holder of the character described, the combination, with a verticallyslotted head, and clamping-bolts mounted and vertically adjustable in said slots and having heads extending beyond the face of the holderhead and horizontally slotted longitudinally of the bolt, of a seat-bar extending through the slots of the bolt-heads and having bearingseats for the article to be clamped near each of its ends, substantially as described.

7. In a boring-tool holder of the character described, the combination, with a verticallyslotted head, and clamping-bolts mounted and vertically adjustable in said slots and having heads extending beyond the face of the holderhead and horizontally slotted longitudinally of the bolt, of a seat-bar extending through the slots of the bolt-heads and having bearingseats for the article to be clamped near each of its ends, said bearing-seats being located on opposite sides of the bolt-heads, substantially as described.

' 8. A boring-tool holder for holding a cylindrical boring-bar, com prising a shank adapted to be held in a lathe-tool post, and a vertical head provided with parallel vertical slots, a clamping-bolt located and vertically adjustable in each slot and having a head horizontally slotted longitudinally of the bolt projecting beyond the front face of the holder-head and adapted to enter the vertical slot in said holderhead, the threaded portion of each bolt projecting beyond the rear face of the holderhead and being provided With a clam ping-nut to bear against said rear face, and a seat-bar extending through the slots in the bolt-heads. recessed to engage said bolt-heads, provided on its front face with bearing-seats for the boringbar located on opposite sides of the bolt-heads, the engaging faces of the seat-bar and bolderhead being horizontally serrated, substantially as described.

9. 'A boring-tool holder for use in connection with lathes, comprising a head and shank adapted to rest on the lathe-slide, the shank extending through and clamped in the toolpost, said head being provided with means for holding the boring instrument, and having at the end thereof nearest the work a downwardly-extending abutment lug or projection to engage and bear against the slide so as to transmit thereto the thrust longitudinally of the boring-tool and prevent rotation of the tool-post thereby, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

'ORRIS Gr. OTEWALT.

Witnesses:

IRVINE MILLER,

GERTRUDE D. YouNe. 

